class A:
    def test(self):
        print("A.test()")

class B:
    def test(self):
        print("B.test()")

    def demo(self):
        print('B demo')

class C(A, B):
    def test(self):
        super().test()
        print('c test()')


if __name__ == '__main__':
    c = C()
    c.test()
    print(C.__mro__)
    c.demo()
